PTT is a service for supporting instantaneous communications between two users in a one-to-one or one-to-group (one-to-many) manner. In general, when a user presses a PTT key of a PTT terminal (e.g., a walkie-talkie unit) the other users tuned on the same frequency or channel can hear the user.
A PTT communication network typically includes a PTT terminal that supports a PTT service and a PTT server for controlling the communication of voice and data in the PTT network. The PTT server also controls the “right to talk” (or right to speak) procedures for each PTT terminal. A user that has been granted the right to talk is said to have been granted the “floor” or a “talk burst”.
A right to talk procedure refers to allocating qualifications for transmitting data in half-duplex communications, such as a PTT service, and is used for preventing collision conditions when more than two users attempt to communicate or transmit data simultaneously. Talk burst requests (or floor requests) from various users are granted or denied by the PTT server such that only one user (PTT terminal) at a time has the right to talk while other users must listen.
In the related art PTT service system, when a user wishes to obtain a right to talk, the user presses a key (e.g., PTT key) of the PTT terminal. If the right to talk has not been allocated to another PTT terminal, the PTT server transmits a talk burst grant message (i.e., floor grant message) to the requesting PTT terminal. However, if another PTT terminal already has received the right to talk, the PTT server transmits a talk burst deny message (i.e., floor deny message) to the corresponding PTT terminal of that user.
The PTT terminal that receives the talk burst grant message from the PTT server is allowed to transmit voice and data to one or more other PTT terminals via the PTT server. The other PTT terminal that receives the talk burst deny message from the PTT server outputs an error message in order to notify the user that the talk burst has been denied. The user then confirms the error message and again requests a right to talk by pressing the key of the PTT terminal waiting until the right to talk of another user is released.
In the related art talk burst allocation method in the PTT service system, a first user who wishes to obtain the right to talk may request a talk burst by pressing the key of the PTT terminal. If a second user has received the right to talk in advance of the first user, the first user must wait until the second user releases his right to talk. Only after the second user has released the line can the first user request a right to talk.
Accordingly, in the related art talk burst allocation method, when a user requests a right to talk, the user may not obtain such right to talk because another user already has the right to talk. In addition, if the user does not press the PTT key soon after deallocation of right to talk to another (i.e., after another user releases his right to talk), the user may lose his chance to other users who may press the PTT key on their PTT terminal more quickly than the first user.
Furthermore, in the related art talk burst allocation method when the user has data high priority, the user may not be able to transmit in advance of others because the right to talk is allocated regardless of the type or priority of data.
Thus, systems and methods are needed to overcome the noted problem.